Prior art teaches preparation of hydroxyl-terminated liquid polymers such as those described in U.S. Pat. Nos. 3,551,471 and 3,551,472, and carboxyl-terminated liquid polymers such as those described in U.S. Pat. No. 3,285,949. Such prior art polymers cure poorly with epoxy resins at room temperature and generally must be reacted at elevated temperatures in the presence of curing agents such as aliphatic or alicyclic amines. The carboxyl-terminated polymers form ester groups when they react with epoxy resins, and the reaction products are rather hydrolytically unstable. Moreover, use of larger amounts of carboxyl-terminated liquid polymers in epoxy resin compositions may require increasingly higher reaction temperatures, e.g., about 80.degree. - 180.degree. C when more than 50 parts carboxyl-terminated liquid polymer (M.sub.n - 2000-5000) is used per 100 parts epoxy resin (epoxy equivalent wt. 160 - 200). New liquid polymer compositions are desired which are room-temperature curable, castable, hydrolytically stable and which generally do not require a catalyst or curing agent.